If you remember a while back Apple held it's WWDC where it announced some stuff one those things being it's new computer OS. While announcing it Apple said that 1 Million people would be able to try the beta out, so if you are one those lucky million then tomorrow is the official day to download the beta. Remember this is a beta and it's unstable it's not recommended to be put on your main machine so if u have a spare laptop sitting around check it out and let me know how it is.......